Precast pipe piles refer to pipe piles prefabricated in factories or construction sites, and precast concrete pipe piles are generally used. The types of precast pipe piles are:
1, China pipe pile
Through the reasonable combination of reinforcement methods and the adjustment of concrete formula, a new type of prestressed concrete pile is produced, which improves the ductility and horizontal bearing capacity of the pile body and is suitable for building pile foundations in areas with earthquake intensity of 8 degrees or above.
2.PHC pipe pile
That is, the prestressed high-strength concrete pipe pile is a hollow cylindrical concrete precast member made by pre-tensioning prestressed centrifugal molding process and steam curing at 10 atmospheric pressure and 180℃.
3.SC pipe pile
SC pipe piles are manufactured by centrifugal process, and the internal concrete is constrained by external steel pipes, which makes the concrete in a three-dimensional stress state, improves the strength, plasticity and toughness of the pipe piles, and has excellent ductility, and is suitable for areas with complex working conditions such as docks and offshore engineering.
4, high performance concrete pipe pile
High-performance concrete pipe piles have good corrosion resistance and frost resistance, and are mainly used in highly corrosive and frozen soil areas.
5, ultra-high strength concrete pipe pile
This is a special pipe pile, which improves the concrete strength of the existing pipe pile from C80 to C 105~C 125, greatly improves the vertical compressive bearing capacity of the pipe pile, and can solve the problem that the pipe pile passes through the dense sand layer and clay layer.
Second, how to make precast concrete pipe piles
Precast concrete pipe piles are generally transported to the construction site for construction after they are manufactured in the factory. So how to prefabricate concrete pipe piles? The manufacturing process of precast pipe piles is divided into the following steps:
1, reinforcing cage binding
The processed main reinforcement is loaded into the disc in the stretching trolley of the binding machine, and the trolley moves at a uniform speed on the transverse guide rail, and the steel bars on the disc are continuously wound around the main reinforcement to form a steel cage.
2, into the mold
After the binding of the reinforcing cage is completed, the reinforcing cage will be hoisted into the precast mould with a truss crane, and both ends will be fixed with ring steel plates and nuts at both ends of the reinforcing cage. After fixation, the reinforcing cage will be hoisted into the concrete pouring area.
3, concrete pouring
After entering the mold, the reinforcing cage is in the concrete concern area, the corresponding pouring car runs on the guide rail on the side of the console, and the exposed concrete at the lower part is gradually filled into the model; After concrete pouring is completed, a circle of cotton thread is wound around the steel formwork, and the other half of the steel formwork is hoisted for sealing.
Step 4 be nervous
The tensioning end of the pipe pile is sent to a special machine for tensioning, and the tensioning degree is determined according to the prefabrication requirements.
5. Centrifugal molding
Put the tensioned pipe pile into a centrifugal tank for centrifugation, and the centrifugation time is generally controlled at about 15 minutes, and the specific time is determined according to the centrifugation rate.
6. Steam curing
Centrifugally formed pipe piles should be cured by steam at normal pressure or high pressure, that is, they should be put into a steam curing pool made of concrete, covered with a concrete cover and cured by steam.
7, demoulding
When the autoclaving time comes, take out the steel formwork and remove the fixing bolts on both sides, so that the prefabricated pipe piles are piled up and transported to the construction site.